" when of equal intensity, things of a more negative nature have a greater effect on one's psychological state and processes than neutral or positive things." -https://en.wikipedia.org/wiki/Negativity_bias

"Research indicates that at the subconscious level, the mind tends to focus on the optimistic; while at the conscious level, it tends to focus on the negative." - https://en.wikipedia.org/wiki/Pollyanna_principle

They never turned it off.

Wait, haven't they been ignoring/deprecating Skype for a couple years now, pushing towards Lync? Or is that only business?

You're so far behind.

They rebranded Lync to Skype for Business, which at least looked like regular Skype, trying to target younger people, but really sucked. Then they abandoned SfB and now we're on Teams, which imitates Slack and integrates SharePoint and all that shit, but works relatively well even if it's UX is pretty poor, there are bugs and it's cloud-only, contrary to the old SfB.

I believe they reset the startup setting then because I noticed this recently after an update and had to turn it off again.